碩士 / 國立臺灣海洋大學 / 海洋生物研究所 / 94 / Abstract
The 4 m French beam trawl and the 3 m ORE beam trawl are common research sampling gears for deep sea biodiversity. The French beam trawl is equipped with a tickler chain, a pair of heavier iron side ski and with a wider opening. The ORE beam trawl is much lighter and with a narrower but higher opening. It is, therefore, appears that the French beam trawl may yield more benthic species in the catches whilst the ORE beam trawl may be able to collect more bathypelagic species. No studies have been, however, conducted to compare the catch composition between these two types of trawls. In the present study, the assemblage structure of the demersal fishes, decapod crustaceans and mollusks in the Taiwan deep waters collected from the French type beam trawl and the ORE type beam trawl were compared at the depth of 250, 500 and 1200 meters. From multivariate analysis, the species abundance of the catches collected by both methods was similar in demersal fishes and decapod crustaceans. But for mollusks the ORE beam trawl collected more species and with high abundance than the French beam trawl. Both methods revealed strong zonation in the three deep-sea benthos assemblages, in which the 250 m yield the higher species richness. As there is no difference overall in the catch composition of demersal fishes and decapod crustaceans between the two types of beam trawl, in terms of the operational aspects and the environment of the Taiwan deep-sea (with lots of sunken wood and mud), the French beam trawl is more robust to use and can operate at cheaper costs.
| Identifer | oai:union.ndltd.org:TW/094NTOU5270009 |
| Date | January 2006 |
| Creators | Pei-Chen Tsai, 蔡佩珍 |
| Contributors | Tin-Yam Chan, 陳天任 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 72 |
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